Electricity & Circuits

Electronics

Published

September 21, 2022

Modified

April 26, 2024

List of quantities, and their units as reference:

Quantity	Symbol	Unit	Abbr.
Voltage	V	Volt	V
Work	W	Joules	J
Charge	Q	Coulomb	C
Current	I	Ampere	A
Resistance	R	Ohms	Ω
Power	P	Watt	W

Electricity

Electricity is associated with the presence of electric charge:

Defined as having voltage and the presence of current
- Think of voltage as pressure. It is measured between two points
- Think of amperes (or amps) as the rate of flow, properly know as current
With flow we describes the movement of electric charges in a conductor
Think of resistance as limiting the flow

Charge (Q) is a property of matter (like mass)…

Positive (+), negative (-) and neutral (absence of a net charge)
…negative charged electrons
- …“orbit” an atoms nucleus with positive charged protons
- …charged particles provide the means to exert electrostatic force
…Coulomb (C) unit of electric charge…
- …⇆ Ampher-hour (Ah) in electrical engineering

Electrostatic force (also called Coulomb’s law)…

…charges of the same type repel
…opposite charges attract one another
…strength of the force is relative to the distance…
- …increases in relation to decreasing distance

Energy

Energy is the capacity to do work…

…flow of charged electrons through a conductor creates electric energy
…converted into different forms of energy…
- …mechanical energy to spin a motor
- …light (electromagnetic energy)
- …battery converts chemical energy into electrical energy

Electric energy begins as electric potential energy…

…energy stored by a charged particle
…set into motion by an electrostatic force …becomes kinetic energy
…moving electric charges do electric work …measured in Volt

The ability of a particle to do work is called electric potential…

…energy a body has because of its physical position
…derived/converted from electric potential energy…
- …combination of electric current and electric potential
- …dissimilar charges have a potential difference (pd)

Electric energy is absorbed or delivered by an electric circuit.

Power

Electric Power (sym. P)

…rate (per unit time) at which electric energy is transferred…
…by an electric circuit to energise electric components
…measured in the unit Watt (abbr. W).

P = V  × I       P (watts) = V  (volts) × I (amps)
P = I² × R       P (watts) = I² (ampes) × R (ohms)
P = V² ÷ R       P (watts) = V² (volts) ÷ R (ohms)

Current

Free (valence) electrons move caused by electrostatic force…

…from atom to atom acting as negative charge carrier
While electrons drift along a chain of atoms within a conductor…
…a continuous flow of electrons is created called electric current
Causes resistive heating (flow of current through a conductor produces heat)
Creates an electromagnetic field (used in motors, inductors, generators)

The flow rate of electric charges through a given area is measured in Coulomb per second, aka Ampere (A):

Amperes, or amps abbreviated to I as constant for current
Why letter I? Current used to be measured by the effect it induced
Lowe-case i intensity, time-varying current

Kirchoff’s Current Law (KCL): The sum of the currents going into a node is zero

Serial components ⇒ Carry the same current
Parallel components ⇒ Total current equals the sum of currents across all components

Voltage

Volt is the unit for an electric potential difference between two points in space

Measures the amount of work required to move an electric charge
Caused by the flow of electric current through a magnetic field
Not an absolute quantity, but a relative value between two points in space
Movement involves a force (unit Newton (N)) and a distance (unit Meter (m))

International unit measured in Joules per Coulomb, aka Volt…

…abbreviated with capital letter V, 1V = 1000mV (millivolt)
Work in joules required to move one coulomb of charge between two points
Voltage difference (potential difference) between two points

Voltage is given as V = W/Q

Kirchoff’s Voltage Law (KVL): The sum of the voltages around any loop is zero

Parallel components ⇒ Same voltage across all components
Serial components ⇒ Total voltage equals the sum of voltages across all components

Conductivity

Not all elemental types of atoms have the same capability to release electrons from their orbit. Electrons orbit with varying distance from the nucleus. The closer the orbit around to the nucleus the stronger the attraction to the center. The outermost electrons on the most distant orbit are called valence electrons.

A material is a better conductor the less electrostatic force is required to move valence electrons to create electric current. In other words a material with low resistance (dt. Wiederstand) is a conductor, and a material with high resistance is an insulator (prevents the flow of electrons).

Resistance

Current flow depends not only on the voltage pushing current around…

…but also on resistance (R) of wires, connections and components
…almost every substance in the world has some form of resistance
…amount of resistance (dt. Wiederstand) of an object determines weather it is…
- …a conductor (low resistance)
- …an insulator (high resistance)

An electric conductor (dt. elektrischer Leiter) is an object/material that allows flow of electric current.

If voltage is applied across a conductor …current will begin to flow
Good conductors are materials with free electrons:
- Metals (copper, aluminium, silver, gold)
- Non-metals (carbon, mercury)
- …some acids and salts

Measured in Ohm represented by the letter omega Ω:

Prefix	Abbr.	Value
Mega	MΩ	10⁶ = 1000000Ω
Kilo	kΩ	10³ = 1000Ω
	Ω	10⁰ = 1Ω
Milli	mΩ	10⁻³ = 0.001Ω
Micro	µΩ	10⁻⁶ = 0.000001Ω

Factors affecting resistance of a material

Length: The longer the material the more resistance it has (directly proportional).
Cross-sectional Area: The thicker the material is he less resistance it has (indirectly proportional).
Type: The material type affects the flow of free electron, hence its quality as capacitor or insulator.
Temperature: Material temperature effects its resistance.

Ohm’s law describes the relation between voltage, current, and resistance:

R resistance of an object (in ohms Ω)
V voltage across object (on volts V)
I Current going through the object (in amperes A)

V = I × R        V (volts) = I (amps) × R (ohms)
I = V ÷ R        I (amps)  = V (volts) ÷ R (ohms)
R = V ÷ I        R (ohms)  = V (volts) ÷ I (amps)

Resistors …passive electrical elements…

…used to reduce voltage or current within a circuit
…resistors which obey Ohm’s law are linear resistors…
- …with a constant resistance (for all voltages and currents)

Semiconductors

Semiconductors have properties between a conductor and an insulator. They isolate until an electric potential difference is applied across the semiconductor material, which allows flow of current:

Elements like silicon have multiple free electrons in their most outer shell (valence shell)
Valence electrons bind with neighboring atoms to form a structure called crystal lattice
An additional element “impurity” is introduced to improve the ability to conduct electricity
Adding impurity to a semiconductor is called doping, the material used is called the donor
A donor adding a surplus of free electrons in the lattice creates an N-type semiconductor
A donor adding an electron hole (missing electron) is known as P-type semiconductor

The most Simple application of a semiconductor is a diode restricting the flow of current in one direction only. Another application is a transistor used to build electronic switches, and signal amplifiers.

Circuits

Simple circuit with red LED, 1kΩ resistor conncted with alligator clips to a 9V block battery

In order for electric current to flow…

…an electric circuit is required
…loop of conductive material to interconnect electrical components…
…which control the current flow to perform a useful task

Electricity is used by electrical components within a circuit

…electricity is required to power an electric circuit
Circuits …store energy or transfer energy to other forms (heat, light, motion)
Energy stored in a circuit is called electric potential energy

Fundamental components are resistors, capacitors and inductors

All electric circuits can be equivalently represented by circuits with these components
Components must add “enough” resistance to prevent the circuit from breaking/overheating

Electric components (aka electronic devices):

Electrical terminals connect a component to a circuit
Components a typically classified into: active, passive, and electromechanical

AC/DC

A voltage source (dt. Spannungsquelle) provides electrical energy:

DC (direct current) (dt. Gleichstrom)
- …for example batteries, solar cells
- …constant voltage …steady stream of electrons in one direction
- …use in digital electronics
AC (alternating current) (dt. Wechselstrom)
- …polarity changes with a frequency …commonly 50Hz (50 times a second)
- …used for transformers in power distribution …motors …domestic appliances

If point A is positive with respect to point B

…moving a positive charge around a circuit from A to B
…or a negative charge from B to A requires work
Difference between the two points called voltage polarity
- …indicated by “plus” + (point A)
- …a negative “minus” - (point B)
- Distinction between + and - called polarity
Closed circuit (dt. geschlossener Stromkreis) …flow of electricity between points A and B
Open circuit …cuts the circuit …prevents flow of electricity (between point A and B)

Conventional Current Flow:

…gives the flow of electrical current from positive to negative
…and Electron Current Flow around a circuit from negative to positive

Ground GND, aka common (dt. Masse)

Most negative point in the circuit with 0V (zero volts)
Reference point (dt. Bezugspotential) to measure voltage and current in a circuit

Integrated Circuit

Integrated Circuits (ICs) are a keystone of modern electronics:

Collection of electronic components: resistors, transistors, capacitors.
Integrated (packaged) into a small chips.
Typical applications:
- Logic gates
- Timers
- Voltage regulators
- Micro controllers
- Micro processors

Packages

The package encapsulates the IC into a single device:

Different packaging types with unique dimensions, mounting-types, and pin-counts.
ICs are polarized and every pin is unique in term of location and function.
Notch and/or dot indicates the first pin.
Pin numbers increased sequentially counter-clockwise around the chip.

Mounting Types

Through-hole components have terminals (lead wires) that are led to the board through holes, and soldered at the opposite side:

Come in two basic types: axial (i.e. resistors) and radial (i.e. capacitors)
Good for manual prototyping, can be used with a breadboard
DIP (Dual Inline Packaging)

SMD (Surface Mounted Devices) are directly soldered to the board than then using hole mounting

Smaller components allows higher component density and more connections
Cheaper components, easier for assembly automation
Components can be placed on both sides of the circuit board
Lower resistance and inductance at the connection
Component-level repair more difficult
Unsuitable for high-power/voltage

DIP

DIP (Dual in-line package), most common through-hole IC package:

Two parallel rows of pins extending perpendicular out or a rectangular plastic housing.
Pins are spaced by 2.54mm standard spacing perfect for breadboards.
Overall size depends on the pin count between 4 up to 64.
The package width allows placement in the center of a breadboard.

Logic Devices

Digital Logic Families:

Classified broadly according to the technology they are build on
Logic families include:
- Diode Logic (DL)
- Resistor-Transistor Logic (RTL)
- Emitter Couple Logic (ECL)
- Transistor-Transistor Logic (TTL)
- CMOS (Complementary Metal Oxide Semiconductor)

Within each family, several subfamilies are available with different:

Propagation delay (speed rating)
- Average transition delay time for the signal from input to output.
- Expressed in nano-seconds (ns)
Power dissipation: Power consumed by the gate when fully driven by all inputs.
Temperature ranges
Voltage level
Current level

Nomenclature

Standardized manufacturer independent numbering scheme for basic parts
Prefix of the part number represents the manufacturer code:
- S Signetics
- SN Texas Instruments
- DM National Semiconductor
The suffix at the end donates the packaging type:
- N plastic dual in line package
- W ceramic flat pack
- D surface mounted plastic package

The middle suffix donates the subfamily:

Suffix	Delay	Power	Comment
74	10ns	10mW	Standard TTL
74L	33ns	1mW	Low-power TTL (replaced by CMOS logic)
74H	6ns	22mW	High-speed TTL
74S	3ns	19mW	Schottky-clamped transistors
74LS	9.5ns	2mW	Low-power Schottky
74ALS	4ns	1mW	Advanced low power Schottky
74F	3.4ns	6mW	reduced propagation delay from LS and ALS
74C			CMOS logic pin compatible to TTL
74HC			CMOS high-speed pin compatible to TTL
74HCT	16ns	1uA	CMOS input/output voltage compatible to TTL

Logic Devices

List of 7400 series integrated circuits:

Name	Comment
74..00	Quad 2-input NAND gate
74..02	Quad 2-input NOR gate
74..04	Hex inverter NOT gate
74..08	Quad 2-input AND gate
74..10	Triple 3 input NAND gate
74..11	Triple 3-input AND gate
74..20	Dual 4-input NAND gate
74..21	Dual 4-input AND gate
74..27	Triple 3-input NOR gate
74..30	Single 8-input NAND gate
74..32	Quad 2-input OR gate
74..260	Dual 4-input NOR gate

Tools

Multimeter

Most essential tool to learn electronics…

“multi” …can measure multiple functions
- Supplied with two meter leads …plug & steal probe
- …some terminate in alligator clips
- Mini-grabbers …little spring-loaded hooks
Today most are digital multimeters…
- …manual ranging …requires the user to choose a value range
- …auto ranging …chooses appropriate value range automatically
Features…
- 4 ports, dedicated mA, A
- Fuse: ceramic (resetable)

List of Functions …typically selected with a dial:

V - Voltage (electrical pressure)
mA/A - Current, Amperage (electrical flow)
Ω - Electrical resistance (in Ohm)
Continuity testing (the meter will beep)
Nice to have…
- Diode testing
- Battery testing
- F - Capacitance (in Farads)
- Temperature (C/F) …component overheating
- Min/Max and Hold …caputre rapidly varying values
- hFE and/or NPN/PNP - Transistor testing
Plug sockets …for the meter leads
- COM common …for the black meter lead
- V/Ω for voltage and resistance
- mA/A for current in a given range

Indication on a digital display…

OL (open leads) …select a different range
Measurement can not be totally precise…
- …goal is to measure as accurate as possible

Voltage

Measuring Voltage …meter must not be entered into the circuit:

It sits outside the circuit …like an observer
Remember that…
- …the circuit must be powered up
- …the meter is set to measure Voltage V
Think of Voltage as pressure
- …measured between two points
- …one has more voltage relative to the other
- …called potential difference
Connecting the meter the wrong way around …measure with minus sign in display

Typically measured between terminals of electric components like resistors, capacitors, and transistors

Current

To measure current, it has to flow through the meter (is inside the circuit):

Caution to much current breaks the fuse inside the meter
Connect black lead to COM …red lead to mA/A sockets

Function Generator

Use
- Generate electrical waveforms, e.g. a sine, triangle, or square
- Provide a signal source with specific voltage applied over a specifiable time period
Features
- Supported waveform types (ramps, noise, programmable)
- Selectable waveform frequencies (e.g. 0.01HZ to 10MHz)
- Selectable waveform amplitude
- Vary frequencies between min/max with a frequency sweep function
- Variable amount of DC voltage with a DC offset function

Oscilloscope

…informally a scope…

Electronic test instrument …debug and analyze circuits

…depicts a repetitive or single waveform
…analyze the relationship between time and voltage
…capture, visualize
- …amplitude, frequency, shape
- …measuring the delays between state changes
- …visualizing the rise and fall times of signals

Display…

..2D graph
- …x-axis time
- …y-axis voltage
…frequency and amplitude of an oscillating signal

Input …signal to be measured

…fed to one of the input connectors
…using…
- …electrical connection
- …banana plugs
- ..specialized cable …probe

Measure…

current & resistance
voltage…
- …magnitude (amplitude) of a signal (peak-to-peak amplitude)
- …highest and lowest voltage of your signal
- …mean and Average Voltages
frequency …number of times per second a waveform repeats
- …period …number of seconds each repeating waveform takes
- duty cycle …ratio of how long a signal is positive VS negative each period
rise & fall time…
- …duration where signals rise to a high point
- …duration where signals fall to a low point

Logic Analyzer

Capture signal from from digital circuits…

…trace and correlate many digital signals simultaneously
…detect and analyze timing violations and transients on buses

Measures and analyzes signals differently than an oscilloscope…

…detects logic threshold levels
…only concerned with the logic states of the signal

References

[pbMe0] Lessons in Electric Circuits, Tony R. Kuphaldt
https://www.ibiblio.org/kuphaldt/electricCircuits

--- title: Electricity & Circuits categories: - Electronics date: 2022/09/21 date-modified: 2024/04/26 toc-expand: 3 --- List of quantities, and their units as reference: Quantity | Symbol | Unit | Abbr. -----------|--------|----------|------ Voltage | V | Volt | V Work | W | Joules | J Charge | Q | Coulomb | C Current | I | Ampere | A Resistance | R | Ohms | Ω Power | P | Watt | W # Electricity Electricity is associated with the presence of electric charge: - Defined as having [voltage](#voltage) and the presence of [current](#current) - Think of voltage as **pressure**. It is measured between two points - Think of amperes (or amps) as the **rate of flow**, properly know as current - With flow we describes the movement of electric charges in a conductor - Think of [resistance](#resistance) as **limiting the flow** **Charge** (Q) is a property of matter (like mass)... * **Positive** (+), **negative** (-) and **neutral** (absence of a net charge) * ...negative charged electrons * ..."orbit" an atoms nucleus with positive charged protons * ...charged particles provide the means to exert electrostatic force * ...**Coulomb** (C) unit of electric charge... * ...⇆ **Ampher-hour** (Ah) in electrical engineering **Electrostatic force** (also called Coulomb’s law)... * ...charges of the same type **repel** * ...opposite charges **attract** one another * ...strength of the force is relative to the distance... * ...increases in relation to decreasing distance ## Energy Energy is the capacity to do work... * ...flow of charged electrons through a conductor creates electric energy * ...converted into different forms of energy... * ...mechanical energy to spin a motor * ...light (electromagnetic energy) * ...battery converts chemical energy into electrical energy Electric energy begins as electric **potential energy**... * ...energy stored by a charged particle * ...set into motion by an electrostatic force ...becomes **kinetic energy** * ...moving electric charges do electric work ...measured in Volt The ability of a particle to do work is called **electric potential**... * ...energy a body has because of its physical position * ...derived/converted from electric potential energy... * ...combination of electric current and electric potential * ...dissimilar charges have a **potential difference** (pd) Electric energy is absorbed or delivered by an electric circuit. ## Power Electric Power (sym. P) * ...rate (per unit time) at which electric energy is transferred... * ...by an electric circuit to energise electric components * ...measured in the unit **Watt** (abbr. W). ```txt P = V × I P (watts) = V (volts) × I (amps) P = I² × R P (watts) = I² (ampes) × R (ohms) P = V² ÷ R P (watts) = V² (volts) ÷ R (ohms) ``` ## Current Free (valence) electrons move caused by electrostatic force… - …from atom to atom acting as _negative charge carrier_ - While electrons drift along a chain of atoms within a conductor… - …a continuous _flow of electrons_ is created called electric current - Causes resistive heating (flow of current through a conductor produces heat) - Creates an electromagnetic field (used in motors, inductors, generators) The _flow rate_ of electric charges through a given area is measured in Coulomb per second, aka **Ampere** (A): - Amperes, or amps abbreviated to **`I`** as constant for current - Why letter I? Current used to be measured by the effect it _induced_ - Lowe-case **`i`** intensity, time-varying current **Kirchoff’s Current Law** (KCL): The sum of the currents going into a node is zero - Serial components ⇒ Carry the same current - Parallel components ⇒ Total current equals the sum of currents across all components ## Voltage Volt is the unit for an electric potential difference between two points in space - Measures the amount of _work_ required to move an electric charge - Caused by the flow of electric current through a magnetic field - Not an absolute quantity, but a relative value between two points in space - Movement involves a force (unit Newton (N)) and a distance (unit Meter (m)) International unit measured in Joules per Coulomb, aka **Volt**… - …abbreviated with capital letter **`V`**, 1V = 1000mV (millivolt) - Work in joules required to move one coulomb of charge between two points - Voltage difference (potential difference) between two points Voltage is given as `V = W/Q` **Kirchoff’s Voltage Law** (KVL): The sum of the voltages around any loop is zero - Parallel components ⇒ Same voltage across all components - Serial components ⇒ Total voltage equals the sum of voltages across all components ## Conductivity _Not all elemental types of atoms have the same capability to release electrons from their orbit. Electrons orbit with varying distance from the nucleus. The closer the orbit around to the nucleus the stronger the attraction to the center. The outermost electrons on the most distant orbit are called valence electrons._ A material is a better conductor the less electrostatic force is required to move valence electrons to create electric current. In other words a material with low resistance (dt. Wiederstand) is a conductor, and a material with high resistance is an insulator (prevents the flow of electrons). ## Resistance Current flow depends not only on the voltage pushing current around… - …but also on resistance (R) of wires, connections and components - …almost every substance in the world has some form of resistance - …amount of resistance (dt. Wiederstand) of an object determines weather it is… - …a **conductor** (low resistance) - …an **insulator** (high resistance) An electric conductor (dt. elektrischer Leiter) is an object/material that allows flow of electric current. - If voltage is applied across a conductor …current will begin to flow - Good conductors are materials with free electrons: - Metals (copper, aluminium, silver, gold) - Non-metals (carbon, mercury) - …some acids and salts Measured in **Ohm** represented by the letter omega **Ω**: | Prefix | Abbr. | Value | |--------|-------|-------------------| | Mega | MΩ | 10⁶ = 1000000Ω | | Kilo | kΩ | 10³ = 1000Ω | | | Ω | 10⁰ = 1Ω | | Milli | mΩ | 10⁻³ = 0.001Ω | | Micro | µΩ | 10⁻⁶ = 0.000001Ω | Factors affecting resistance of a material - Length: The longer the material the more resistance it has (directly proportional). - Cross-sectional Area: The thicker the material is he less resistance it has (indirectly proportional). - Type: The material type affects the flow of free electron, hence its quality as capacitor or insulator. - Temperature: Material temperature effects its resistance. **Ohm’s law** describes the relation between voltage, current, and resistance: - `R` resistance of an object (in ohms Ω) - `V` voltage across object (on volts V) - `I` Current going through the object (in amperes A) ```txt V = I × R V (volts) = I (amps) × R (ohms) I = V ÷ R I (amps) = V (volts) ÷ R (ohms) R = V ÷ I R (ohms) = V (volts) ÷ I (amps) ``` **Resistors** ...passive electrical elements... * ...used to reduce voltage or current within a circuit * ...resistors which obey Ohm's law are **linear resistors**... * ...with a constant resistance (for all voltages and currents) ## Semiconductors Semiconductors have properties between a conductor and an insulator. They isolate until an electric potential difference is applied across the semiconductor material, which allows flow of current: - Elements like silicon have multiple free electrons in their most outer shell (valence shell) - Valence electrons bind with neighboring atoms to form a structure called **crystal lattice** - An additional element "**impurity**" is introduced to improve the ability to conduct electricity - Adding impurity to a semiconductor is called **doping**, the material used is called the **donor** - A donor adding a surplus of free electrons in the lattice creates an **N-type** semiconductor - A donor adding an electron hole (missing electron) is known as **P-type** semiconductor The most Simple application of a semiconductor is a **diode** restricting the flow of current in one direction only. Another application is a **transistor** used to build electronic switches, and signal amplifiers. # Circuits ![Simple circuit with red LED, 1kΩ resistor conncted with alligator clips to a 9V block battery](_images/simple-circuit.jpg){fig-align="center"} In order for electric current to flow… - …an electric circuit is required - …**loop of conductive material** to interconnect electrical components… - …which control the current flow to perform a useful task Electricity is used by electrical components within a circuit - …electricity is required to **power an electric circuit** - Circuits …store energy or transfer energy to other forms (heat, light, motion) - Energy stored in a circuit is called electric potential energy Fundamental components are resistors, capacitors and inductors - All electric circuits can be equivalently represented by circuits with these components - Components must add "enough" resistance to prevent the circuit from breaking/overheating Electric **components** (aka electronic devices): - Electrical **terminals** connect a component to a circuit - Components a typically classified into: **active**, **passive**, and **electromechanical** ## AC/DC A **voltage source** (dt. Spannungsquelle) provides electrical energy: - DC (direct current) (dt. Gleichstrom) - …for example batteries, solar cells - …constant voltage …steady stream of electrons in one direction - …use in digital electronics - AC (alternating current) (dt. Wechselstrom) - …polarity changes with a frequency …commonly 50Hz (50 times a second) - …used for transformers in power distribution …motors …domestic appliances If point A is positive with respect to point B - …moving a positive charge around a circuit from A to B - …or a negative charge from B to A requires work - Difference between the two points called **voltage polarity** - …indicated by "plus" **+** (point A) - …a negative "minus" **-** (point B) - Distinction between + and - called polarity - **Closed circuit** (dt. geschlossener Stromkreis) …flow of electricity between points A and B - **Open circuit** …cuts the circuit …prevents flow of electricity (between point A and B) **Conventional Current Flow**: - …gives the flow of electrical current from positive to negative - …and **Electron Current Flow** around a circuit from negative to positive Ground **GND**, aka common (dt. _Masse_) - Most **negative** point in the circuit with **0V** (zero volts) - **Reference** point (dt. Bezugspotential) to measure voltage and current in a circuit # Integrated Circuit Integrated Circuits (ICs) are a keystone of modern electronics: * Collection of electronic components: resistors, transistors, capacitors. * Integrated (packaged) into a small chips. * Typical applications: - Logic gates - Timers - Voltage regulators - Micro controllers - Micro processors ## Packages The **package** encapsulates the IC into a single device: * Different [packaging types][01] with unique dimensions, mounting-types, and pin-counts. * ICs are **polarized** and every pin is unique in term of location and function. * **Notch** and/or **dot** indicates the first pin. * Pin numbers increased sequentially counter-clockwise around the chip. ### Mounting Types **Through-hole** components have terminals (lead wires) that are led to the board through holes, and soldered at the opposite side: - Come in two basic types: axial (i.e. resistors) and radial (i.e. capacitors) - Good for manual prototyping, can be used with a breadboard - **DIP** (Dual Inline Packaging) **SMD** (Surface Mounted Devices) are directly soldered to the board than then using hole mounting - Smaller components allows higher component density and more connections - Cheaper components, easier for assembly automation - Components can be placed on both sides of the circuit board - Lower resistance and inductance at the connection - Component-level repair more difficult - Unsuitable for high-power/voltage ### DIP [DIP][02] (Dual in-line package), most common through-hole IC package: * Two parallel rows of pins extending perpendicular out or a rectangular plastic housing. * Pins are spaced by 2.54mm standard spacing perfect for breadboards. * Overall size depends on the pin count between 4 up to 64. * The package width allows placement in the center of a breadboard. ## Logic Devices Digital Logic Families: * Classified broadly according to the technology they are build on * Logic families include: - Diode Logic (DL) - Resistor-Transistor Logic (RTL) - Emitter Couple Logic (ECL) - Transistor-Transistor Logic (TTL) - CMOS (Complementary Metal Oxide Semiconductor) Within each family, several subfamilies are available with different: * Propagation delay (speed rating) - Average transition delay time for the signal from input to output. - Expressed in nano-seconds (ns) * Power dissipation: Power consumed by the gate when fully driven by all inputs. * Temperature ranges * Voltage level * Current level ### Nomenclature * Standardized manufacturer independent numbering scheme for basic parts * Prefix of the part number represents the **manufacturer code**: - **S** Signetics - **SN** Texas Instruments - **DM** National Semiconductor * The suffix at the end donates the **packaging type**: - **N** plastic dual in line package - **W** ceramic flat pack - **D** surface mounted plastic package The middle suffix donates the **subfamily**: | Suffix | Delay | Power | Comment | |----------|-------|-------|---------------------------------------------------------------| | 74 | 10ns | 10mW | Standard TTL | | 74L | 33ns | 1mW | Low-power TTL (replaced by CMOS logic) | | 74H | 6ns | 22mW | High-speed TTL | | 74S | 3ns | 19mW | Schottky-clamped transistors | | 74LS | 9.5ns | 2mW | Low-power Schottky | | 74ALS | 4ns | 1mW | Advanced low power Schottky | | 74F | 3.4ns | 6mW | reduced propagation delay from LS and ALS | | 74C | | | CMOS logic pin compatible to TTL | | 74HC | | | CMOS high-speed pin compatible to TTL | | 74HCT | 16ns | 1uA | CMOS input/output voltage compatible to TTL | ### Logic Devices List of 7400 series integrated circuits: | Name | Comment | |-----------|-----------------------------| | 74..00 | Quad 2-input NAND gate | | 74..02 | Quad 2-input NOR gate | | 74..04 | Hex inverter NOT gate | | 74..08 | Quad 2-input AND gate | | 74..10 | Triple 3 input NAND gate | | 74..11 | Triple 3-input AND gate | | 74..20 | Dual 4-input NAND gate | | 74..21 | Dual 4-input AND gate | | 74..27 | Triple 3-input NOR gate | | 74..30 | Single 8-input NAND gate | | 74..32 | Quad 2-input OR gate | | 74..260 | Dual 4-input NOR gate | [01]: https://en.m.wikipedia.org/wiki/List_of_integrated_circuit_packaging_types [02]: https://en.m.wikipedia.org/wiki/Dual_in-line_package [03]: https://en.m.wikipedia.org/wiki/7400_series [04]: https://en.wikipedia.org/wiki/4000_series [05]: https://en.wikipedia.org/wiki/HCMOS # Tools ## Multimeter Most essential tool to learn electronics… - "multi" …can measure multiple functions - Supplied with two **meter leads** …plug & steal probe - …some terminate in alligator clips - Mini-grabbers …little spring-loaded hooks - Today most are digital multimeters… - …manual ranging …requires the user to choose a value range - …auto ranging …chooses appropriate value range automatically * Features… - 4 ports, dedicated mA, A - Fuse: ceramic (resetable) List of Functions …typically selected with a dial: - **V** - Voltage (electrical pressure) - **mA**/**A** - Current, Amperage (electrical flow) - **Ω** - Electrical resistance (in Ohm) - Continuity testing (the meter will beep) - Nice to have… - Diode testing - Battery testing - **F** - Capacitance (in Farads) - Temperature (C/F) …component overheating - Min/Max and Hold …caputre rapidly varying values - **hFE** and/or **NPN**/**PNP** - Transistor testing - Plug sockets …for the meter leads - **COM** common …for the black meter lead - **V**/**Ω** for voltage and resistance - **mA**/**A** for current in a given range Indication on a digital display… - **OL** (open leads) …select a different range - Measurement can not be totally precise… - …goal is to measure as accurate as possible ### Voltage Measuring Voltage …meter must _not_ be entered into the circuit: - It sits outside the circuit …like an observer - Remember that… - …the circuit must be powered up - …the meter is set to measure Voltage **`V`** - Think of Voltage as pressure - …measured between two points - …one has more voltage relative to the other - …called _potential difference_ - Connecting the meter the wrong way around …measure with minus sign in display Typically measured between terminals of electric components like resistors, capacitors, and transistors ### Current To measure current, it has to _flow through_ the meter (is inside the circuit): - **Caution** to much current breaks the fuse inside the meter - Connect black lead to COM …red lead to mA/A sockets ## Function Generator * Use - Generate electrical **waveforms**, e.g. a sine, triangle, or square - Provide a signal source with specific voltage applied over a specifiable time period * Features - Supported **waveform types** (ramps, noise, programmable) - Selectable waveform **frequencies** (e.g. 0.01HZ to 10MHz) - Selectable waveform **amplitude** - Vary frequencies between min/max with a **frequency sweep** function - Variable amount of DC voltage with a **DC offset** function ## Oscilloscope ...informally a scope... Electronic test instrument ...debug and analyze circuits * ...depicts a repetitive or single waveform * ...analyze the relationship between time and voltage * ...capture, visualize * ...amplitude, frequency, shape * ...measuring the delays between state changes * ...visualizing the rise and fall times of signals Display... * ..2D graph * ...x-axis **time** * ...y-axis **voltage** * ...frequency and amplitude of an oscillating signal Input ...signal to be measured * ...fed to one of the input connectors * ...using... * ...electrical connection * ...banana plugs * ..specialized cable ...**probe** Measure... * current & resistance * voltage... * ...magnitude (amplitude) of a signal (peak-to-peak amplitude) * ...highest and lowest voltage of your signal * ...mean and Average Voltages * **frequency** ...number of times per second a waveform repeats * ...period ...number of seconds each repeating waveform takes * **duty cycle** ...ratio of how long a signal is positive VS negative each period * rise & fall time... * ...duration where signals rise to a high point * ...duration where signals fall to a low point ## Logic Analyzer Capture signal from from digital circuits... * ...trace and correlate many digital signals simultaneously * ...detect and analyze timing violations and transients on buses Measures and analyzes signals differently than an oscilloscope... * ...detects logic threshold levels * ...only concerned with the logic states of the signal # References [pbMe0] Lessons in Electric Circuits, Tony R. Kuphaldt <https://www.ibiblio.org/kuphaldt/electricCircuits>